Java - calculate nth Fibonacci number

[Hercuflea]

Homework Statement

Hello everyone, I am trying to write a java program that asks the user to input a number n, and the computer calculates the nth Fibonacci number. I am supposed to use a loop to calculate the problem.

My question is, how do I set up the loop to calculate the nth Fibonacci number? I know how to do all of the program except the loop.

Homework Equations

I want to use the "for" loop.

The Attempt at a Solution

import java.util.Scanner;

public class Assignment2 {
public static void main(String [] args) {
Scanner input = new Scanner(System.in);

System.out.print("Enter a number n in order to calculate the nth Fibonacci number: ");
int n = input.nextInt();

for(int i = 0; i;){}

System.out.println("The " + n + "th Fibonacci number is: ");

}
}

 

[Mark44]

Homework Statement

Hello everyone, I am trying to write a java program that asks the user to input a number n, and the computer calculates the nth Fibonacci number. I am supposed to use a loop to calculate the problem.

My question is, how do I set up the loop to calculate the nth Fibonacci number? I know how to do all of the program except the loop.

Homework Equations

I want to use the "for" loop.

The Attempt at a Solution

import java.util.Scanner;

public class Assignment2 {
public static void main(String [] args) {
Scanner input = new Scanner(System.in);

System.out.print("Enter a number n in order to calculate the nth Fibonacci number: ");
int n = input.nextInt();

for(int i = 0; i;){}

System.out.println("The " + n + "th Fibonacci number is: ");

}
}

When you post code, put it inside [noparse]

[/noparse] tags. This makes your code easier to read, by preserving your indentation (if you used any).

You can't write a program to calculate Fibonacci numbers if you don't know how to calculate them yourself. What are the first few numbers in a Fibonacci sequence?

 

[Hercuflea]

When you post code, put it inside [noparse]

[/noparse] tags. This makes your code easier to read, by preserving your indentation (if you used any).

You can't write a program to calculate Fibonacci numbers if you don't know how to calculate them yourself. What are the first few numbers in a Fibonacci sequence?

a1 = 0, a2 = 1, a3 = 1, a4 = 2, a5 = 3, a6 = 5, ...etc. adding the last two numbers to get the nth number.

 

[gabbagabbahey]

a1 = 0, a2 = 1, a3 = 1, a4 = 2, a5 = 3, a6 = 5, ...etc. adding the last two numbers to get the nth number.

Usually the indices start at zero, so that $F_0=0$, $F_1=1$, $F_2=1$, $F_3=2$,etc.

I would suggest that you store all calculated Fibonacci numbers in an array of Integers. To start with, you will need to initialize the array to include $F_0$ and $F_1$. Then, to calculate the nth number, you first look in the array to see if it has already been calculated; if yes then simply output that entry in the array, if no, then start with the last 2 entries in the array an calculate and store (in the array) all the remaining numbers up until the nth number.

 

[rezeew]

Hi there, to set up a loop to calculate the nth Fibonacci number, you can use the following approach:

1. Declare three integer variables, let's say "a", "b", and "c", and initialize "a" and "b" to 0 and 1 respectively.

2. Use a for loop with the loop condition as "i < n", where "i" is the loop variable.

3. Inside the loop, assign the value of "a" to "c" and then assign the value of "a + b" to "a".

4. Finally, assign the value of "c" to "b".

5. After the loop, the value of "a" will be the nth Fibonacci number, so you can print it out using the System.out.println() statement.

Your code should look something like this:

int a = 0; // first Fibonacci number
int b = 1; // second Fibonacci number
int c; // temporary variable
for(int i = 2; i < n; i++) { // loop from 2 to n
c = a; // assign value of a to c
a = a + b; // calculate the next Fibonacci number and assign it to a
b = c; // assign the value of c to b
}
System.out.println("The " + n + "th Fibonacci number is: " + a); // print the result

Hope this helps! Let me know if you have any further questions.